use uuid::Uuid;

use crate::error::AppError;
use crate::models::common::TargetType;
use crate::models::issues::IssueReaction;
use crate::service::IssueService;
use crate::session::Session;

use super::util::{clamp_limit_offset, ensure_affected, required_text};

#[derive(serde::Deserialize, serde::Serialize, Clone, Debug, utoipa::ToSchema)]
pub struct CreateIssueReactionParams {
    pub content: String,
    pub target_type: Option<String>,
    pub target_id: Option<Uuid>,
}

impl IssueService {
    pub async fn issue_reactions(
        &self,
        ctx: &Session,
        wk_name: &str,
        number: i64,
        limit: i64,
        offset: i64,
    ) -> Result<Vec<IssueReaction>, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let issue = self.resolve_issue(wk_name, number).await?;
        self.ensure_issue_readable(user_uid, &issue).await?;
        let (limit, offset) = clamp_limit_offset(limit, offset);

        sqlx::query_as::<_, IssueReaction>(
            "SELECT id, issue_id, user_id, content, target_type, target_id, created_at \
             FROM issue_reaction WHERE issue_id = $1 ORDER BY created_at ASC LIMIT $2 OFFSET $3",
        )
        .bind(issue.id)
        .bind(limit)
        .bind(offset)
        .fetch_all(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)
    }

    pub async fn issue_add_reaction(
        &self,
        ctx: &Session,
        wk_name: &str,
        number: i64,
        params: CreateIssueReactionParams,
    ) -> Result<IssueReaction, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let issue = self.resolve_issue(wk_name, number).await?;
        self.ensure_issue_readable(user_uid, &issue).await?;

        let content = required_text(params.content, "content")?;
        let target_type = params
            .target_type
            .as_deref()
            .and_then(|s| s.parse::<TargetType>().ok())
            .unwrap_or(TargetType::Issue);
        if target_type == TargetType::Unknown {
            return Err(AppError::BadRequest("invalid target_type".into()));
        }

        let now = chrono::Utc::now();
        sqlx::query_as::<_, IssueReaction>(
            "INSERT INTO issue_reaction (id, issue_id, user_id, content, target_type, target_id, created_at) \
             VALUES ($1, $2, $3, $4, $5, $6, $7) \
             RETURNING id, issue_id, user_id, content, target_type, target_id, created_at",
        )
        .bind(Uuid::now_v7())
        .bind(issue.id)
        .bind(user_uid)
        .bind(&content)
        .bind(target_type)
        .bind(params.target_id)
        .bind(now)
        .fetch_one(self.ctx.db.writer())
        .await
        .map_err(AppError::Database)
    }

    pub async fn issue_remove_reaction(
        &self,
        ctx: &Session,
        wk_name: &str,
        number: i64,
        reaction_id: Uuid,
    ) -> Result<(), AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let issue = self.resolve_issue(wk_name, number).await?;
        self.ensure_issue_readable(user_uid, &issue).await?;

        let result = sqlx::query(
            "DELETE FROM issue_reaction WHERE id = $1 AND issue_id = $2 AND user_id = $3",
        )
        .bind(reaction_id)
        .bind(issue.id)
        .bind(user_uid)
        .execute(self.ctx.db.writer())
        .await
        .map_err(AppError::Database)?;
        ensure_affected(
            result.rows_affected(),
            "reaction not found or not authored by you",
        )
    }
}